A storage array system is a storage system that includes multiple storage devices and advanced functionality. A storage array often includes a storage array controller that manages the storage devices and presents them to a server or computing device as one or more logical storage volumes. Storage arrays often provide data protection far beyond what is achievable with single storage devices. Thus, storage arrays are ubiquitous wherever data protection is concerned.
A widespread standard of configuration of multiple storage devices is RAID (“redundant array of independent disks” or “redundant array of inexpensive disks”). RAID architectures provide high levels of storage reliability from an arrangement of multiple storage devices combined as a single logical storage volume using specialized hardware or software. RAID architectures are generally characterized as providing redundancy through mirroring or parity. If one, or sometimes even two, of the storage devices in many RAID architectures fails, it can be replaced without losing data stored in the array and often without taking the other storage devices offline.
As the acronym suggests, storage array systems have typically included computer or server grade magnetic hard disk drives. Magnetic disks provide high capacity storage devices at a relatively low cost. Other storage devices, such as solid-state media, provide performance benefits such as faster input/output response than magnetic disks and potentially longer life expectancy. Solid-state media is often much more expensive per data unit, i.e. cost per byte, than magnetic media, and the performance gains come with a high price. There is a reluctance to replace the magnetic disks in storage array systems with solid-state media devices.